Valve seat construction

ABSTRACT

A butterfly valve in which the vane seat is formed of a corrosion resistant stainless steel ring compressedly interlocked axially onto the valve body.

United States Patent 1 Montesi 11 3,749,359 [4 1 July 31,1973

[ VALVE SEAT CONSTRUCTION [75] Inventor: Robert Paul Montesi, Bradford,Pa. [73] Assignee: Dresser Industries, Inc., Dallas, Tex.

[22] Filed: Mar. 24, 1971 [21] Appl. No.: 127,621

[52] 11.8. C1. 251/306 [51] Int. Cl. Fl6k 1/226 [58] Field 01 Search251/288, 305, 306,

[56] References Cited UNITED STATES PATENTS 3,511,474 5/1970 Miner251/305 2,907,548 10/1959 Maas et al. 251/173 X 3,077,331 2/1963 Burtis251/173 3,414,234 12/1968 Henrion 251/173 Primary Examiner-Henry T.Klinksiek Attorney-Robert W. Mayer, Thomas P. Hubbard, .lr., DanielRubin, Raymond T. Majesko, Roy L. Van Winkle, William E. Johnson, Jr.and Eddie E. Scott I 5 7 ABSTRACT A butterfly valve in which the vaneseat is formed of a corrosion resistant stainless steel ringcompressedly interlocked axially onto the valve body.

16 Claims, 8 Drawing Figures 4?- FLOW PAIENIEnJum ma 3,749,359 sum 1 or3 ELI-3P5 ROBERT P. MONTESI INVENTOHZ PATENTEDJUL31 um SHEET 3 0F 3 FIG.7

FIG. 8

INVENTOR:

ROBER'F R MONTESI ATTORNEY VALVE SEAT CONSTRUCTION CROSS-REFERENCES TORELATED APPLICATIONS None BACKGROUND OF THE INVENTION 1. The field ofart to which the invention pertains includes Valves and Valve actuationas contained in Patent Office class 251.

2. The prior art to which the invention is directed includes the art ofbutterfly valves being of a type in which a usually circular vane ordisc is rotatable in a fluid body passage between an open and closedposition. When in the closed position, the vane engages a seat withwhich it cooperates to provide a seal against leakage of the pressurizedline contents intended to be controlled by the valve. It is desirable ifnot essential in valves of this type that the seal be effective on eachoccasion of valve closing for the life of the valve to con tinuouslyprovide positive shutoff without frequency maintenance and servicing ofthe seat. Because the seat is commonly subjected to wearing conditionscaused by factors such as wire drawing, corrosion, temperature changes,abrasion and the like, it is desirable to provide an ideal seat which iscompletely unaffected by these environmental factors. Accordingly, ithas long been recognized that the seat should comprise a hard, durablecorrosion resistant material able to at least substantially retain itsmachine-finished surface to withstand normal and conventional conditionsand provide trouble-free service for very prolonged operating periods.Previous efforts to achieve this result have included the use ofpremachined alloyed materials for the seat placed into the valve body asa production step subsequent to the casting of the valve body bycementing or the like. This has achieved only a limited success for ashort time following manufacture because of the inability of the cementto maintain its bond for the life of the valve. Leakage occurs as thebond, affected by the adverse conditions of use, begins to fall,frequency after only a short time period of operative service. Likewise,various techniques for mechanically attaching a seat ring in a valvebody have been utilized as, for example, disclosed in US. Pat. Nos.1,909,478 and 3,511,474. The former is particularly adpated for areciprocably movable coaxial valve stem in supporting the seat ring on acompressible resilient base while the latter utilizes circumferentialcold forging for radially condensing the seat ring material onto a bodyreceiving surface. A technique for east fusing a body to its seat ringis disclosed in US. Pat. No. 3,525,499.

SUMMARY OF THE INVENTION This invention relates to valves and to theprocess of their manufacture. More particularly, the invention relatesto butterfly valves and the process of producing butrerfly valves inwhich a valve seat of hard, durable corrosion resistant material ismechanically secured to the valve body in a metal-to-metal axiallylocked compression interfit therewith. In the manner of the invention aring of stainless steel or the like is pre-formed to initially receivean annular support boss or rib integralof the valve body and projectingradially inward of the fluid passage at a predefined axial displacementrelative to the turning axis of the closure vane. When in place on thesupport rib, the ring is axially bent until compressedly interlockedagainst the rib in a double flanged axially compressed gripping relationtherewith. It has been found that not only does this construction afforda concentrically accurate seating surface for the vane with a high orderof permanence in protecting the rib support against effects ofcorrosion, but that it achieves these benefits at substantially reducedfabrication cost as compared to prior art techniqes without condensingthe seat metal and without sacrifice in valve quality. Moreover, suchseating construction is readily usable with butterfuly valves even whenof a wafer construction (axially thin stock without end connections) inwhich placing an annular seat is axially critical and most difficult inview of stock thinness.

It is therefore an object of the invention to provide a novel valveconstruction having a durable, corrosion resistant seat ring materialsuch as stainless steel mechanically secured to the valve body of castiron or the like in an economical manner without the attendant specialtechniques previously required.

It is a still further object .of the invention to provide improvedbutterfly valves having an annular seat ring as in the last mentionedobject affording a high defree of permanence in protecting the body seatsupport against effects of corrosion and the like.

BRIEF DESCRIPTION OFTI-IE DRAWINGS FIG. 1 is a plan sectional view of awafer type butterfly valve with parts partially broken away;

FIG. 2 is a sectional view taken substantially along the lines 2-2 ofFIG. 1;

FIG. 3 is an enlarged view of the vane and seat engagement whereencircled in FIG. 2;

FIG. 4 is a radial section through the seat ring before being attachedto the valve body; A

FIG. 5 is a fragmentary enlargement of the encircled shell portion ofFIG. 4;

FIG. 6 illustrates apparatus for attaching the seat ring to the valvebody in the preferred embodiment;

FIG. 7 is a' fragmentary enlargement of the encircled portion of FIG. 6;and

FIG. 8 is an alternative structural embodiment to that of the previousFigs.

Referring now to FIG. 1, there is illustrated a butterfly valve whichincludes a housing or casing referred to generally by the referencecharacrer C." The casing includes an annular body wall 10 preferably ofa cast material such as ductile iron or cast iron of A126 or A48commercial grade. Secured to the body wall is a seat generallydesignated 11 juxtaposed to radial body end face 12 and formed inaccordance with the invention as will be described below. Atdiametrically opposite points with respect to the seat, the wall 10includes aligned cylindrical bores 13 sized to accommodate Teflon(trademark) or the like antifriction bearing sleeves 14 and enlarged attheir outer ends to provide counterbores 15. The main valve cross-shaftis designated 16 and is of a noncircular formation throughout itslength. Carried by the ends of shaft 16 within bores 13 are corrosionresistant bearing sleeves 17, preferably of a corrosion proof materialsuch as stainless steel. Each sleeve has a nonicircular central borecorresponding to the shape of shaft 16 to receive and complement theshaft therethrough as to constitute the driving connection between theshaft and bearing sleeve. The outer sleeve surface is cylindrical and isjournaled within Teflon sleeve 14.

The vane, as can be seen also in FiG. 2, is referred to in its entiretyby the reference character V. it includes a central cavity 18 throughwhich shaft 16 passes and is formed with opposite internal hubs 19. Thehubs in turn are formed with noncircular bores 20 corresponding to thecross section of the shaft 16 received therein to establish a drivingconnection between the shaft and vane member.

At the outer end of each bore 20, there is included a counter bore 21partially receiving bearing sleeve 17 and a static seal 22 likewisefitted therein. Positioned in each counter 15 is an outer seal 23, whichgenerally comprises rubber or other suitable eiastomeric matcriai, topervent leakage of fluid from interior of the housing. At one side, seal23 is held in position by a cover plate 24 secured to the housing bymeans of bolts 9. The seal 23 on the other side is held in position in asimilar manner by a base plate 25 associated with the valve operatingmechanism and secured to the housing by bolts 26.

Mounted on base plate 25 is a housing 27 for the valve operatingmechanism generally designated as 0. This latter housing defines achamber in which vane shaft 16 is received through base plate 25 foroperatively opening and closing the valve vis a wrench engaging memberin a manner, as for example, disclosed in U.S. Pat. No. 3,420,500.

The vane and seat construction with which the invention hereof isconcerned can be more readily undervane 32. Boss 50 initiates frombottom to top (as viewed in the drawings) in a radial shoulder 51merging via radius 52 into a radially inward sloping axially extendingportion 53 of an angular offset comparable to angle alpha in order tocomplementarily accommodate the exterior of ring seat portion 45 whenapplied thereto. Surface 53 terminates with an annular intemai recess 56in which is contained an annular O-ring or other resilient type gasketsealing member 57. From above recess 56 the boss surface comprises anaxially extending section 58 connecting via a radius 59 with a radiallyinward sloping axial surface 60 being on the order of about 60 axialoffset.

To secure seat ring 40 to valve body boss 50 there is employed avertically secured lower die punch 65 annularly recessed at 66 near itstop to closely accommodate the interior surface portions 44 and 45 ofring 40. With ring 40 axially in place on surface 66 of die 65, valvebody 10 with gasket 57 contained in recess 56 is coaxiaily placed in afloating relation superimposed onto the ring until body shoulder 51 isin surface engagement against the exterior radial surface of ring flange44. With the body and ring in place an upper cosxially aligned verticalextending die punch 70 having an annular dished surface 71 generallycontoured in geometric correspondence to radius 59 and slope 60 isdownwardly advanced toward a forming stroke to engage bendable ringsection 46.

Secured coaxisily in a surrounding relation to upper stood withreference to their post-assembly attachment die 70 for advancementtherewith is a preload member illustrated in FIGS. 2 and 3. As thereshown, vane V includes a face 32, a generally circular periphery 33 anda notch-like annular recess 34 at its peripheral corner in which issecured a rubber or other suitable type gasket 35. The gasket has anouter rounded or beveled edge which when the vane is in closed positionengages seat ring of seat 1 1 formed in accordance with the inventionhereof. A clamp means in the form of a ring 4! embeds against thebsckface of the gasket and a screw 42 passes through aligned openings tosecure the gasket to the vane. As illustrated in these Figures, thevaneis positioned to close the valve against fluid flow. When the vane isrotated through a 90 angular displacement by means of operatingmechanism "0," the valve is opened to its maximum flow position.

Seat ring 40, as most clearly shown in FIGS. 4 and 5, is in a preferredembodiment a durable, highly corrosion proof stainless steel compositionof commercially available grade. Type 504 annealed stainless of about1/16 inch wall thickness has been found particularly suitable for thesepurposes and is initially cut from tubular stock after which it is coldrolled to provide an acceptable finish. When initially fonned forpurposes hereof the ring has a radially extending flange 44 merging witha radially inward sloping axial seating section in turn merging with ebendsbiy deformable axiel section 46. The axial offset slope of seatingsection 45 is represented by the angle alpha and is predetermined toclosely match the rotational closure path of vane gasket edge 35. in acommercial embodiment, angle alpha is on the order of about 16'.

Attschment of ring 40 to the valve body 10 can best be understood withreference to FIGS. 6 end 7. To receive the ring, body 10 includes anintegral radially inward extending seat support in the form of a rib orboss surface-machined prior to ring attachment to a high degree ofaccuracy with respect to the center line of 73 adapted to engage andpreload body 10 against 7 lower die before the bending of ring section46 begins. Prelosding to on the order of about 8,000 pounds serves tomaintain a flrm engagement between the ring and body during the formingstep as to preclude any relative slippage therebetween that mightotherwise occur. For this purpose member 73 includes a spring pad in theform of an annular ring 74 surrounding the lower end of die and having aforward end face 75 normally dependent in a plane below that of die endface 72. Pad 74 is secured at a plurality of angulariy displacedlocations via a screw 76 to a piston 78 compressibly received withinnitrogen spring assembly 79. By this means pad face 75 engages body face12 prior to the forming operation as die 70 moves downward toward die65. Further downward advancement of die 70 causes pad 74 to preload thebody and ring until the desired magnitude of preload is achieved. In thelatter condition the axial displacement between the die and pad is fromthe relation illustrated solid to the relation at which the opposite padface is illustrated dashed.

Thereafter downward movement of die punch 70 is continued until apredetermined forming load is applied es die end face 72 approaches theradial end face 67 of die punch 65. in the course of die movement. ringend 46 is bent radially outward from the position shown solid to theposition shown dashed in FIG. 7. Die 70 and its integral preload member73 are thereafter withdrawn after which body 10 with seat 40 attached toboss 50 is lifted off punch 65,to complete the assembly.

The entire attachment step including set up time can be completed inapproximately one minute.

in deforming ring 40 for attachment in the manner 5 Just described, end46 is bowed or flared about a clearance 77 into an engagement with bosssurfbce 60 whereby not to condense metal in the process. in the courseof deforming an axial grip results between the ring and portions of boss50. While on removing die 70 a degree of minimal springback is thoughtto occur between ring end 46 and contiguous boss surface 60, the axialgrip is firmly maintained about and radially beyond radii 52 and 59.Thus by this means the bent ring with its structural integrity in tactforms a double flanged axial grip in a metal-to-metal compressioninterlock with boss 50. The magnitude of formed interlock is sufficientto positively prevent inadvertent rotation of the ring while at the sametime avoiding infiltration of line content between the ring and bodywhereby to preclude corrosive action from occuring therebetween.Moreover, by virtue of the metal-to-metal contact, the likehihood ofring damage from foreign objects apt to become lodged between the ringand vane during operation is extremely minimal. in order to insure theproper magnitude of compressive interlock between ring 40 and boss 50 ithas been found that the radial component of bent flange 46 should have adimension Y greater than the ring cross-sectional thickness diminsion Xon the order of at least 2 to 1.

Reference is now made to FIG. 8 in which there is disclosed analternative form of the invention generally not preferred over thatdisclosed in FIGS. 1-7. In this embodiment, valve body 10, includes anannular recess 80 in which to receive a secured annular resilientgasketv material 81. The radial inner gasket surface is sloped at 82 toafford continuity conformance with the flow passage contour thereat andis adapted to be engaged by a corrosion proof type vane tip in the formof a ring 83. The latter ring preferrably corresponds in composition toring 40 and is bent in an analogous manner onto a more or lesssemi-circular annular vane boss 84 recessed circumferentially to receivethe ring in the manner shown.

By the above description there has been disclosed a novel constructionfor mechanically securing a seat material of .corrosion proofcomposition onto a valve body such as cast iron in a manner providing acompressive axial interlock therebetween. By virtue of a double flangedformation in a metal-to-metal axially compressive grip formed betweenthe ring and valve body boss provided to support the ring, the assemblycan be relatively easily and quickly manufactured to a high degree ofpermanency and accuracy relative to the vane axis and at comparably lesscost than that previously encountered. By the simplicity of thisconstruction therefore, there is economically produced a high qualityvalve having a suitable corrosion type surface for line content such aswater mains or the like. At the same time it is capable of beingproduced accurately within narrow axial limits such as is demanded in awafer type valve body.

Since many changes could be made in the above construction and manyapparently widely different embodiments of this invention could be madewithout departing from the scope thereof, it is intended that all mattercontained in the drawings and specification shall be interpreted asillustrative and not in a limiting sense.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

l. A butterfly valve comprising in combination:

a. a body defining a fluid passage between an inlet and outlet;

b. a vane member supported in said passage and operable between a firstposition in which said passage is open to fluid flow and a secondposition in which said passage is closed to fluid flow;

. a corrosion resistant metal sealing ring extending exposed in saidfluid passage fixedly secured to a metal support on one of said vanemember or said body in a compressive metal-to-metal axial grip relationtherewith, said secured ring having a crosssectional thicknesssubstantially retained from when unsecured to said support; and

d. an annular resilient gasket seal member extending exposed in saidfluid passage and secured to the other of to cooperate with said sealingring vane member or .said body, said seal member being adapted to whensaid vane member is in said second position for effecting shutoff ofsaid passage to fluid flow.

2. A butterfly valve according to claim 1 in which said sealing ring isfixedly secured to the vane member about its circumference and saidgasket seal member is secured to said body.

3. A butterfly valve according to claim 1 in which said sealing ring issecured to said body and said gasket seal member is fixedly secured tothe vane member about the circumference thereof.

4. A butterfly valve according to claim 3 in which said body includes anintegral substantially annular raidally inward extending projection towhich said sealing ring is secured.

5. A butterfly valve according to claim 4 in which said projectionincludes an axially intermediate annular recess and an annular resilientgasket material is contained in said recess compressed in sealingrelation underlying against said sealing ring.

6. A butterfly valve according to claim 4 in which said body is of castiron and said sealing ring is of stainless steel fixedly secured to saidprojection to comprise the seat for said valve. I

7. A butterfly valve according to claim 6 in which at least the surfaceportion of said seat adapted to cooperate with the gasket seal member onsaid vane includes an axial offset generally superimposed to the closurepath of said vane in moving from said first to said second positions.

8. A butterfly valve'according to claim 7 in which said projectionincludes an axially intermediate annular recess and an annular resilientgasket material is contained in said recess compressed in sealingrelation underlying against seat.

9. A butterfly valve according to claim 1 in which said secured ring isof substantially uniform cross sectional thickness.

10. In a butterfly valve including a metal body defining a fluid passagebetween an inlet and outlet and a vane member supported in said passageand operable between a first position in which said passage is open tofluid flow and a second position in which said passage is closed tofluid flow, the improvement comprismg:

an annular metal ring of material different than said body and supportedon one of said vane or said body for cooperation with a resilient gasketmember on the other of said vane or said body when said vane is in saidsecond position, said ring being fixedly secured to its support in acompressive metal-to-metal axial grip relation therewith and having across-sectional thickness substantially retained from when unsecured toits support.

11. In a butterfly valve according to claim 10 in which said ring isfixedly secured to said body to comprise the seat of said valve.

12. In a butterfly valve according to claim 11 in which said bodyincludes an annular integral seat support projecting radially inward ofsaid passage at a predetermined location relative to said vane memberand to which said seat is fixedly secured.

13. in a butterfly valve according to claim 12 in which said seat isgenerally double flanged U-shaped in material cross-sectional axiallygripping said seat supcross-section thickness.

* I! i i 1U UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTIONPatentNo. 3,7 l9,359 3 uly 31, 1973 Inventor( RObe It Paul Montesi It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

1. Column 6, line 1H,, cancel "to cooperate with said sealing ring" andsubstitute said-.

D 2. Column 6, lime 16, after "to" irise'rt -cooper'ate with I saidsealing ring-.

Signe and sealed this 20th day of November 1973.

(SEAL) Attst:

EDWARD "M.FLETCHER,JR. I RENE -D. TEGTMEYER Attesting Officer 'ActingCommissioner of Patents

1. A butterfly valve comprising in combination: a. a body defining a fluid passage between an inlet and outlet; b. a vane member supported in said passage and operable between a first position in which said passage is open to fluid flow and a second position in which said passage is closed to fluid flow; c. a corrosion resistant metal sealing ring extending exposed in said fluid passage fixedly secured to a metal support on one of said vane member or said body in a compressive metal-to-metal axial grip relation therewith, said secured ring having a cross-sectional thickness substantially retained from when unsecured to said support; and d. an annular resilient gasket seal member extending exposed in said fluid passage and secured to the other of to cooperate with said sealing ring vane member or said body, said seal member being adapted to when said vane member is in said second position for effecting shutoff of said passage to fluid flow.
 2. A butterfly valve according to claim 1 in which said sealing ring is fixedly secured to the vane member about its circumference and said gasket seal member is secured to said body.
 3. A butterfly valve according to claim 1 in which said sealing ring is secured to said body and said gasket seal member is fixedly secured to the vane member about the circumference thereof.
 4. A butterfly valve according to claim 3 in which said body includes an integral substantially annular raidally inward extending projection to which said sealing ring is secured.
 5. A butterfly valve according to claim 4 in which said projection includes an axially intermediate annular recess and an annular resilient gasket material is contained in said recess compressed in sealing relation underlying against said sealing ring.
 6. A butterfly valve according to claim 4 in which said body is of cast iron and said sealing ring is of stainless steel fixedly secured to said projection to comprise the seat for said valve.
 7. A butterfly valve according to claim 6 in which at least the surface portion of said seat adapted to cooperate with the gasket seal member on said vane includes an axial offset generally superimposed to the closure path of said vane in moving from said first to said second positions.
 8. A butterfly valve according to claim 7 in which said projection includes an axially intermediate annular recess and an annular resilient gasket material is contained in said recess compressed in sealing relation underlying against seat.
 9. A butterfly valve according to claim 1 in which said secured ring is of substantially uniform cross-sectional thickness.
 10. In a butterfly valve including a metal body defining a fluid passage between an inlet and outlet and a vane member supported in said passage and operable between a first position in which said passage is open to fluid flow and a second position in which said passage is closed to fluid flow, the improvement comprising: an annular metal ring of material different than said body and supported on one of said vane or said body for cooperation with a resilient gasket member on the other of said vane or said body when said vane is in said second position, said ring being fixedly secured to its support in a compressive metal-to-metal axial grip relation therewith and having a cross-sectional thickness substantially retained from when unsecured to its support.
 11. In a butterfly valve according to claim 10 in which said ring is fixedly secured to said body to comprise the seat of said valve.
 12. In a butterfly valve according to claim 11 in which said body includes an annular integral seat support projecting radially inward of said passage at a predetermined location relative to said vane member and to which said seat is fixedly secured.
 13. In a butterfly valve according to claim 12 in which said seat is generally double flanged U-shaped in material cross-sectional axially gripping said seat support in compression between said flanges.
 14. In a bufferfly valve according to claim 13 in which said seat support includes an axially intermediate annular recess and an annular resilient gasket material is contained in said recess compressed in sealing relation underlying against said seat.
 15. In a butterfly valve according to claim 14 in which said body is cast iron and said seat is of stainless steel.
 16. In a butterfly valve according to claim 10 in which said secured ring is of substantially uniform cross-section thickness. 